Panel mounting for variable-circuit elements



May 5, 1925. 1,536,840

A. H. GREBE PANEL MOUNTING FOR VARIABLE CIRCUIT ELEMENTS Filed Dec. 1924ORNEY Patented May 5, 1925.

ALFRED HENRY GREBE, OF HOLLIS, NEW YORK.

PANEL MOUNTING FOR VARIABLE-CIRCUIT ELEMENTS.

Application filed December 5, 1924. Serial No. 754,193.

To all whom 'it may concern.'

Be it known that I, ALFRED HENRY GREBE, a citizen of the United States,residing at Hollis, in the county of Queens and State of New York, haveinvented certain new and useful Improvements in Panel Mountings forVariable-Circuit Elements, of which the following is a specification.

My invention relates generally to panel mounting of controlling dialsfor condensers, inductance coils, resistances and other circuit elementsof variable type and is designed to facilitate manipulation, nicety ofadjustment, etc., and, at the same time, improve the appearance of thepanel, by relieving it of the conventional full-face display of numerousdials of various shapes and sizes.

The invention has particular reference to the panel mounting of mainco-ntrolling dials, having arranged in cooperative relation therewith,Vernier attachments, the function and operation of which are Welllrnownin the art.

The novelty of the present invention lies broadly in mounting both themain and Vernier dials in the rear of the panel, preferably at rightangles to the plane thereof, and, thus arranged, they are concealed fromview, excepting a small peripheral section of each dial, which projectsthrough a conforming slot in the panel, presenting what is termed atangent wheel adjustment.

In the accompanying drawings, I have illustrated a construction suitablefor carrying my invention into effect, but I do not wish to beunderstood as limiting myself to the same, as various changes may bemade the-rein without departing from the spirit and scope of theinvention.

In the drawings- Fig. l is sectional view taken transversely of a panel,showing main and Vernier dials,

mounted in the rear of the panel in accord-V ance with my invention tocontrol the variame member of a circuit element, such as a condenser orother unit;

ig. 2 is a vertical sectional View taken on the line 2, 2, of Fig. 1,and

Fig. 3 is a horizontal section taken on the line 3, 3, of Fig. 2.

Referring now to the drawings, 1 may represent the panel of a radioreceiving set, for example, and 2, a variable condenser or other circuitelement or unit,such as an inductance, a resistance or the like,suitably mounted in or on the rear of the panel and having the movablemember thereof carried by a shaft 3.

As shown, the adjustment of the movable member of the variable elementis cont-rplled by main and Vernier dials 4 and 5; the main dial beingmounted on the shaft and the vernier dial on a second parallel shaft ti.carrying at its upper end a friction pinion 7, of any suitable form,which o"- gijages the wall 8, of an annular groove 9. in the under faceof the main dial 4. The Vernier dial shaft tn rns in slotted bearings10, 10, formed in the frame 11 of the circuit ele-ment 2, and isyieldingly held in close fric/tional contact with the groove of the maindial by a spring 12. y

Mounted as above described, segments of the main and the vernier dialsproject through slots 13 and 13a, in the panel, which slots, by means ofintegral or attached facings 14 are extended to conform approximately tothe projecting segments, leaving exposed only the peripheral surface ofthe dial segments for manipulation by the hand of the operator.

The peripheral face of the main dial contains the usual scale or degreemarkings from zero to one hundred, as indicated at 15, in Fig. 1, andfor greater convenience of the operator, the peripheral face of theVernier dial may be milled, toothed or otherwise roughened to insure agood finger grip for ease of manipulation.

In use, a tangent wheel adjustment is provided, either directly by themain dial or indirectly, by the Vernier dial, which, under manipulationby the finger of the operator, is effective for rotating the movablemember of the variable circuit element, in either direction, throughoutits range of movement and such manipulation is very materiallyfacilitatedby the slot facings 14, which serve both as guides andguards, in locating the dials 'and providing convenient support for theoperators hand.

In applying the above described construction throughout the panel of aradio receiving set, for example, the objectionable dial display, whichis noticeably prominent in apparatus of this kind, is avoided and aneffective adjustment, controlled to permit the smallest fraction of aturn, is made available for ready and convenient use by anyone ofaverage ability, not specially skilled in the art. Y

Having, therefore, described my invention, what 1 claim is: ,y

1. A panel mounting for a variable circuit element, comprising two dialsoperatively connected to control the variable element, said dialspresenting segmental portions only `for manipulation from the front ofthe panel. v

2. A panel mounting for a variable circuit element comprising two dialsmounted in the rear of the panel and operatively connected to control'the variable element, said dials being arranged with segmental portionsonly available for manipulation from the front of the panel.

3. A panel mounting for a variable circuit element, comprising two dialsmounted in the rear of the panel and operatively connec'ted to controlthe variable element, said dials being geared together and havingsegmental portions extending through openings in the panel.

4. A panel mounting for a variable circuit element, comprising two dialsmounted in the rear. ofthe panel and operatively connected to controlthe variable element, Said dials being connected by reducing gearing andhaving segmental portions projecting through openings in the panel andmeans for extending the front lface of the panel to enclosesubstantially all of said segmental -portions excepting the peripheralsurfaces thereof. n

5. A panel mounting for a variable circuit element, comprising twodialsmounted in the rear of the panel and operatively connected to controlthe variable element, said

